Module 1 Introduction to Radiation

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Module 1Introduction to Radiation
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Introduction to Radiation

• Terminal Objective
• DEFINE the fundamentals of radiation, radioactive
  material, ionization, ionizing radiation, and
  contamination.

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Enabling Objectives

• LIST the three basic components of an atom.
• DESCRIBE the differences between ionizing
  radiation and non-ionizing radiation.
• DEFINE radioactivity.

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Enabling Objectives

• STATE the four basic types of ionizing radiation.
• DESCRIBE the shielding materials and biological
  hazards for each of the four types of ionizing
  radiation.
• LIST the three techniques for minimizing exposure
  to radiation and radioactive material (ALARA).

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Radiation Basics Video
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Parts of an Atom

• Protons
• Neutrons
• Electrons

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Protons
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Neutrons
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Electrons
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Stable and Unstable Atoms

• An atom with too many or too few neutrons
  contains excess energy and is not stable.
• Unstable atoms give off excess energy
  (radiation).
• Unstable atoms are radioactive.

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Ionization
Radiation

• Removing electrons from atoms or molecules

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Ionizing Radiation
Excess energy (from unstable atoms), capable of
removing electrons from an atom
Radiation
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Non-Ionizing Radiation
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Radioactivity

• Radioactivity is the process of unstable
  (radioactive) atoms trying to become stable by
  emitting ionizing energy.

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Radioactive Material

• Radioactive Material
• Material containing unstable (radioactive) atoms
• Radioactive Contamination
• Radioactive material in an unwanted place

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Radiological vs. Nuclear

• Radiological deals with radiation or material
  that emits radiation.
• Example Radiological WMD Dirty Bomb
• Nuclear refers to processes that involve
  splitting a nucleus (fission) or combining nuclei
  of atoms (fusion).
• Example Nuclear WMD atomic bomb

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Measuring Radiation

• Radiation Dose
• Radiation energy absorbed by the human body
• Dose is measured in units of rem.
• A millirem (mrem) is one thousandth of a rem.

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Measuring Radiation

• Radiation Dose Rate
• Radiation energy received over a period of time
• Radiation dose rate is dose per time
• mrem per hour mrem/hr strength of
  radiation at a location

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Types of Ionizing Radiation
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Types of Ionizing Radiation

• Alpha radiation
• Beta radiation
• Gamma rays/X-rays
• Neutron radiation
• Some radioactive materials may emit more than one
  kind of radiation

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Alpha Radiation

• Range
• 1 to 2 inches
• Shielding
• Paper, Cloth,
• Dead Layer of Skin

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Alpha Radiation (continued)

• Biological Hazard
• Not an external radiation hazard
• Easily stopped by the dead layer of skin
• Internal hazard If material is inside the body,
  then the alpha radiation reaches live cells.

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Alpha Radiation (continued)

• Sources
• Uranium (nuclear power plant fuel and nuclear
  weapons)
• Plutonium (nuclear weapons)
• Americium (smoke detectors)
• Thorium (high-temperature metals)

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Beta Radiation

• Range
• about 10 feet
• Shielding
• Thick Clothing, ¼ Inch Aluminum, ¼ Inch
  Plastic

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Beta Radiation (continued)

• Biological Hazard
• External hazard to skin and eyes
• Internal hazard if the material that emits the
  beta radiation is inside the body. Then beta
  radiation can deposit energy in a small area of
  body tissue.

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Beta Radiation (continued)

• Sources
• Used nuclear reactor fuel
• Nuclear weapons fallout (strontium)
• Some industrial radioactive sources such as
  cesium
• Tritium in glow-in-the-dark EXIT signs, watch
  dials, and night-sights on firearms
• Radioactive nickel in chemical agent detectors

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Gamma Rays/X-Rays

• Range
• Hundreds of feet
• Shielding
• Inch of Lead, 3 Inches of Steel, 6
  inches Concrete, 1 foot of Dirt

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Gamma Rays/X-Rays (continued)

• Biological Hazard
• Gamma rays and X-rays easily penetrate body
  tissues, outside or inside of the body.
• Whole body (internal and external) hazard
•  

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Gamma Rays/X-Rays (continued)

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• Sources
• Uranium, plutonium, radioactive cobalt, and
  cesium
• Industrial radiation sources 
• Medical sources, cancer treatment machines
• Many beta-emitters also emit gamma radiation.
• Potassium in soil, bananas, and potassium
  chloride (salt substitute)

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Neutron Radiation

• Range
• Hundreds of feet
• Shielding
• 10 Inches of Plastic, 1 foot of Concrete, 3
  feet of Dirt, 3 feet of Water

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Neutron Radiation (continued)

• Biological Hazard
• Whole body hazard (external and internal neutrons
  are a whole body hazard).
• Neutrons penetrate body tissues.
• Neutrons cause damage whether the material is
  inside or outside of the body.

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Neutron Radiation (continued)

• Sources
• Nuclear reactions inside nuclear reactor while
  reactor is operating
• Burst of radiation from exploding nuclear weapon
• Plutonium, industrial sources, moisture gauges
  with californium or mixture of americium and
  beryllium

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Comparison of Ionizing Radiation
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Particle Size Comparison
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Alpha, Beta, and Neutron Particles
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Comparison of Radiation and Contaminants

• Radiation is energy.
• Radioactive contaminants are materials that emit
  radiation.
• Radioactive contaminants are radioactive atoms
  that get onto something unwanted or are in an
  uncontrolled place.
• Radioactive atoms cannot be neutralized to make
  them non-radioactive.

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Exposure vs. Contamination
External Exposure
External Contamination
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Internal Contamination and Internal Exposure
Radioactive material inside the body Both
contaminated and exposed
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ALARA

• As
• Low
• As
• Reasonably
• Achievable

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ALARA Video
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ALARA

• Minimize time
• Maximize distance
• Use shielding

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Review

• Whats the difference if I get exposed or if I
  get contaminated?
• How do I protect myself from alpha, beta, gamma,
  or neutron radiation?
• How can I practice the principles of ALARA in
  this situation?

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Questions?